Q: I changed my device (or wiped my device), how to restore my purchases?

A: Make sure you are using the same account than initially used to purchase the packs.
Then, you just tap the pack as if you would buy them again. The store (Google Play, iTunes or Amazon AppStore) will see that you already own the item and you will not be charged twice. It will unlock the item in-game.
Please note it's not possible to restore purchase between different stores (such as from iOS to Android).

Q: When purchasing a level pack on Google Play, I get the message "You already own this item" and it doesn't unlock.

A: This happens rarely when there is a connection issue with Google Play at the time of purchase. Your purchase has been properly processed. Usually, the problem resolves itself by waiting a few hours. However, here are some actions that have been working to help the game detect the purchase faster:

• Quitting the game entirely (by pressing back until the popup "Do you want to quit?" appears and tapping yes) and restarting
• Rebooting the device
• Clearing the Google Play Store cache and data. To do that, perform the following steps: (Warning: you will need to re-enter your credentials when running Google Play Store again).
  • From the Home screen, tap the Menu key.
  • Tap Settings, then More.
  • Tap Application Manager.
  • Swipe left until you're in All tab.
  • Scroll to and tap on Google Play Store.
  • Tap Force Close first.
  • Then, tap Clear Data button.
  • Reboot the phone.
  • Launch the Play Store.
  • Setup your account.
  • Download the item.

Q: How to backup/restore my progression between different devices? (instructions for Thermometers Puzzles)

A: If you are using the Google Play version of the game, you can transfer your progress from one Android device to another. You have to use Google Play Games "Saved Games" feature.
On the main menu of the game, tap on the "settings" button then on the "Google Play" icon. From there, you can use your Google Play Games account to upload your save to the cloud. On your new device, make sure you use the same Google Play Games account and use the option "load from cloud" to restore your progress.